#include <iostream>

 #include <cstdio>

 #include <cstring>

 #include <cmath>

 #include <algorithm>

 #include <climits>

 #include <vector>

 #include <queue>

 #include <cstdlib>

 #include <string>

 #include <set>

 #include <stack>

 #define LL long long

 #define pii pair<int,int>

 #define INF 0x3f3f3f3f

 using namespace std;

 const int maxn = ;

 int n,d[maxn];

 int main() {

     while(~scanf("%d",&n)){

         for(int i = ; i <= n; i++)

             scanf("%d",d+i);

         int ans = INF;

         sort(d+,d+n+);

         for(int i = ; i < n; i++){

             int tmp = ,ds = d[i+] - d[i];

             for(int j = i - ; j > ; j--)

                 if(d[i] - d[j] == ds*(j - i)) continue;

                 else tmp++;

             for(int j = i + ; j <= n; j++)

                 if(d[j] - d[i+] == ds*(j - i - )) continue;

                 else tmp++;

             ans = min(ans,tmp);

         }

         printf("%d\n",ans);

     }

     return ;

 }